var obj= {
    name:'小李',
    age:'18',
    birth:'2002-05-01',
    'middle school' :'向上中学'

};

console.log('toString' in obj); //true

console.log(obj.hasOwnProperty('age')); //true
console.log(obj.hasOwnProperty('toString')) //false
//console.log('name' in obj);

//console.log('toString' in obj);//true


